我们 does not include the person whom the speaker is talking to 咱们 is all inclusive. If you want to include the person you are talking to in the "we" use 咱们, otherwise you are referring to a group that does generally not include the person addressed.

usually， we use “我们” it is more formal。 "咱" “咱们” are more oral. not everybody in China will use these words. the two words are most used in the north of China

exactly the same方言